I tested Deskmate 2 and Windows 2.03 with Tandy 1000 SL/2. Both of them uses the 10h 640x200 4 color video mode.
I compared the two applications with PCEM and Dosbox.

In PCEM the menus and calendar of Deskmate 2 has a yellow background and the some buttons being white, on Dosbox is the opposite the background of the calendar is white.
When comparing the Windows 2.03 Tandy 640x400x4 video mode on PCEM and Tandy the green color in PCEM is red on dosbox and vice versa white and blue colors are correct.

PD: I was not being able to upload the two Win 2.03 images for comparison, it seems that only 3 screenshot can be uploaded.

I believe the Dosbox implementation is correct because on Deskmate 2 the background of the calendar is white, as is supposed to be. The same problem is on Deskmate 3 when the 640x200x4 video mode is used, but It does not affects the 11h video mode 640x200x16 of the SL/2 or the "standard" 320x200x16 mode.
Here some screenshots